Sewing machines typically include a knife blade for cutting the trailing threads after an article has been sewn. These threads are gathered and pressed against the knife blade by the operator or the knife is pressed against the threads manually or using hand held scissors. In industrial settings where throughput is important, this is a time consuming operation which typically causes delays, particularly when the knife blade becomes dull and must be replaced or sharpened. Also, with manual operation, the neatness of the cut may vary from operator to operator.